Mere Christianity was published by Geoffrey Bles in 1952, assembling and revising material from three earlier slim volumes — Broadcast Talks (1942), Christian Behaviour (1943), and Beyond Personality (1944) — which were themselves based on talks Lewis delivered on the BBC during World War II. The book has since become the most widely read work of Christian apologetics of the twentieth century, responsible for more conversions (by anecdotal report) than any other single text, and a permanent fixture on the shelves of believers and skeptics alike.
The Book
Lewis structures his argument with characteristic clarity. Book I (“Right and Wrong as a Clue to the Meaning of the Universe”) argues from the existence of a universal moral sense — the Moral Law — to the existence of a moral Lawgiver. Book II (“What Christians Believe”) moves from theism to specifically Christian belief, presenting the “trilemma” argument: Jesus claimed to be God; therefore he was either a liar, a lunatic, or Lord — there is no room for the comfortable position that he was “a great moral teacher” who was not divine. Book III (“Christian Behaviour”) discusses Christian ethics. Book IV (“Beyond Personality”) explains the Trinity and the process of becoming “little Christs.”
The BBC talks were addressed to a general audience — many of whom were not Christian — and this shows in the style. Lewis avoids theological jargon, uses homely analogies (a house, a tin soldier, a fleet of ships), and anticipates objections. The tone is conversational, reasonable, and remarkably persuasive even to readers who resist the conclusions.
Themes
Natural Law — Lewis’s foundational argument rests on the claim that all humans share an innate moral sense that cannot be explained by biology alone. This “Law of Human Nature” points to a Lawgiver.
The trilemma — the argument that Jesus must be liar, lunatic, or Lord has been endlessly debated, attacked (most notably by philosophers who point out the false trichotomy), and defended. It remains the most famous argument in popular apologetics.
“Mere” Christianity — Lewis deliberately avoids denominational disputes, presenting only the beliefs shared by all Christians. This ecumenical approach — “mere Christianity,” a term borrowed from Richard Baxter — broadened the book’s appeal across Protestant, Catholic, and Orthodox audiences.
Collecting Mere Christianity
First edition (Geoffrey Bles, London, 1952): Blue cloth with dust jacket. First printing has “1952” on title page.
Market values (with dust jacket):
- Fine in dust jacket: $3,000–$8,000
- Very good in dust jacket: $1,000–$3,000
- Without dust jacket: $200–$500
First American edition (Macmillan, New York, 1952): $1,000–$3,000 in dust jacket.
Earlier component parts — Broadcast Talks (Geoffrey Bles, 1942), Christian Behaviour (1943), Beyond Personality (1944): $500–$2,000 each in dust jacket.
The book’s continuous popularity — it has never been out of print and sells hundreds of thousands of copies annually — means that first editions are the primary collecting focus. Signed copies are rare and highly prized.